title: Yield and proliferation rate of adipose-derived stromal cells as a function of age, body mass index and harvest site-increasing the yield by use of adherent and supernatant fractions?
abstract: OBJECTIVE
  Adipose-derived stem cells are easily accessed and have a relatively high density compared with other mesenchymal stromal cells. Isolation protocols of adipose-derived stem cells (ASC) rely on the cell's ability to adhere to tissue culture plastic overnight. It was evaluated whether the floating ASC fractions are also of interest for cell-based therapies. In addition, the impact of age, body mass index (BMI) and harvest site was assessed.
  
  
  METHODS
  The surface protein profile with the use of flow cytometry, the cell yield and the doubling time of passages 4, 5 and 6 of ASC from 30 donors were determined. Adherent and supernatant fractions were compared. The impact of age, BMI and harvest site on cell yield and doubling times was determined.
  
  
  RESULTS
  Both adherent and supernatant fractions showed high mean fluorescence intensities for CD13, CD29, CD44, CD73, CD90 and CD105 and comparatively low mean fluorescence intensities for CD11b, CD62L, intracellular adhesion molecule-1 and CD34. Doubling times of adherent and supernatant fractions did not differ significantly. Whereas the old age group had a significantly lower cell yield compared with the middle aged group, BMI and harvest site had no impact on cell yield. Finally, doubling times for passages 4, 5 and 6 were not influenced by the age and BMI of the donors, nor the tissue-harvesting site.
  
  
  CONCLUSIONS
  The floating ASC fraction is an equivalent second cell source just like the adherent ASC fraction. Donor age, BMI and harvest site do not influence cell yield and proliferation rate.
authors.affiliation: Division of Plastic and Hand Surgery, University Hospital Zurich, Zurich, Switzerland. johanna.buschmann@usz.ch
authors.forename: Johanna
authors.initials: J
authors.lastname: Buschmann
authors.forename: Shuping
authors.initials: S
authors.lastname: Gao
authors.forename: Luc
authors.initials: L
authors.lastname: Härter
authors.forename: Sonja
authors.initials: S
authors.lastname: Hemmi
authors.forename: Manfred
authors.initials: M
authors.lastname: Welti
authors.forename: Clement M L
authors.initials: CM
authors.lastname: Werner
authors.forename: Maurizio
authors.initials: M
authors.lastname: Calcagni
authors.forename: Paolo
authors.initials: P
authors.lastname: Cinelli
authors.forename: Guido A
authors.initials: GA
authors.lastname: Wanner
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism / Q000502:physiology*; D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000378:metabolism; D015992:Body Mass Index; D018929:Cell Culture Techniques / Q000379:methods; D049109:Cell Proliferation; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013234:Stem Cells / Q000378:metabolism / Q000502:physiology*
chemical_list: D015703:Antigens, CD
keywords: adipose tissue; cell yield; mesenchymal stromal cells; proliferation rate